I'm sorry DH, but I just named a few players... Notice that I didnt even name players like Pierce, Huber, Coetzer, Tauziat, Turnbull etc, all of them very good players.
I know Seles is still a very good player, but I dont think she can be considered in the "justine-kim-etc" generation. Another example is Graf, included in the late 80's early 90's. She won a GS title in 1999, obviusly she was still a great player. I just want you to note that it's very difficult to especify which generation a player belongs to.
I also included Court in the "before 70's" but of course she was still an awesome player in the early 70's! In fact she was still world number one in 1974, but she played most of her tennis in the 60's.